Driving gear for material feeders for sewing machines



J 1930- I R. 'MUNDLOS 1,762,880

DRIVING GEAR FOR MATERIAL FEEDERS FOR SEWING MACHINES Filed Jan. 10. 1928 ,24 .43 J (/2 n20 ,42 I' r I 3 W 6 Q g 1161 116424 Patented June 19, 1930 res BUDOLF MUNDLOS, on MAGnEBune, "G RMANY DRIVING GEAR FOB MATERIAL FEEDEBS FOR SEWING MACHINES Application filed January 10, 1928, Serial No. 245,759, and in Germany November 18, 1926.

This invention relates to sewing machines 'by means of which two thread lock stitches and zig-zag lines of stitches. can be made, i. e..

producing a reciprocating movement in ver-- tical direction by means of a cam or finger on the main shaft, situated underneath thematerial-feeder, and it has also been proposed to derive from the oscillating shaft the movement of the material-feeder transversely 130' the longitudinal direction of the machine. The driving mechanisms of known type do not work accurately enough as they comprise too great moving masses, which render the working of the machine unsteady.

According to the invention the longitudinal shifting of the material-feeder is pr0- duced by an oscillating link which transmits its movement by a connecting rod upon a rocking shaft adapted to be shifted in longitudinal direction. Owing to the rocking movement of this shaft the connecting rod must be composed of two parts, the one part of the rod being rotatable in the other part of the rod but not shiftable in longitudinal direction. of two arms arranged on the rockingshaft and designed as bearings for a pivot bolt over which grips a sleeve of the holder of the material-feeder.

By the longitudinal movement of the rocking shaft a longitudinal movement is im- 49 parted also to the material-feeder,atransverse movement of the material-feeder being produced by the rocking movement "of the rocking shaft. 2 i w 7 I When the size of the moving'masses which is small in this form of construction, has to be reduced to a minimum, not the whole rocking shaft, but only the short portion of the same which carries the oscillatable arms is made movable in longitudinal direction.

An embodiment of the invention is il- Fig. 3 shows a constructional detail on en- 'larged scale.

' vide 'a bore 11 and a cavity 11 duced end which'passes through" the bore The connecting rod acts on one lustrated, byway of example, in the accompanying drawing, inwhich v i 1 is-a rear-elevation of the machine. Fig. 2' is a plan-view of the same, viewed from below. 7

The main shaft 1 is journaled in two bearings 2 and 3 which are fixed on the machine frame. On this main shaft a pinion 4 is keyed which meshes with a spur-wheel 6 held in a bearing 5. Rigid with this spur wheel 6 is a cam disk 7 which guides a stud 9 'ofa link 10. The link 10 is pivotally maintained by a stud 8 and is oscillated when the bolt is moved by the cam disk 7. A connectingrod is composed of two parts 11 andll the part 11 ofsaid connecting rod being connected directly with an arm 12 on a shaft 13 The 5 arms are reciprocated by the two part con:

nectingrod, the part 11 being maintained in position to which it has been adjusted,

and its head-11 'isso constructed as to pro- 11 has a "screw threaded end portion 'which is engaged by anut 11 which is located in'thecavity =11. The'nut 11 "connects the parts so that'the part of the rod 11 can turn in the head 11 but not execute a" The 'removement in longitudinal direction with regard to the rod 11..

The part 11 of the'rod has at its front end a head 11 which grips or surrounds a portion' of one of the arms'12 on the rocking. shaft 13 The cam groove in the disk 7 actuates the link 10 and the connectingrod 11,

11 An oscillating movement is 'communi cated to the arm 12 through connections to I the member 24:. The rotative par-t 11 of the rod allows the arm 12 to oscillate freely. The r f arm 12 being rigid with the rocking shaft 18 this shaft is shifted by. the movement of the rod 11. The part 13? of the rock shaft 13 has thereon the. arms 12,: a

which carry a bar 20, upon which is mounted a part 21 of a material feeder. The part 13 of the shaft 13 is reciprocatory longitudinally by the cam 7 and link 10 to reciprocate the material feed to produce zigzag stitches of a length which may be varied in accordance with the setting of the rod in the slot of the link 10 by which the length of reciprocation of the part 13 of the shaft is effected.

Inorder that the mass to be moved does not become too great, one can, as shown in Fig. 1, make the shaft 13 in two parts. The one part 13 is not shiftable in longitudinal direction and executes merely a rocking movement. The part 13' is mounted on the bolt 14: so that it can be shifted in longitudinal direction and is connected to the part 13 by a coupling 16, 17. The'part 13 of the shaft has an arm 16 on which a bolt 17 is fixed. This bolt 17 projects through an arm 18 of the part 13 of the rocking shaft, said arm having, same as the part 13, a bore designed to receive the bolt 15. The shaft is held at the middle by a bearing 19.

The pivot-bolt 20, mounted in the two arms 12, carries a sleeve 21 to which the materialfeeder 22 is fixed. The to and fro movement of the material-feeder 22 is produced by the connecting rod 11, acting upon the arms 12 of the rocking shaft 13.

To the material-feeder a movement transversely to the longitudinal direction is communicatedat the same time through the oscil lating movement of shaft 13 and consequently of the arms 12 and bolt 20. The movement of the material-feeder is controlled by a cam 23 on the main shaft 1. The rocking shaft 13 is driven, in a manner known per se, from the main shaft by a lever system which acts upon a lever 24; of said shaft 13.

I claim In a driving gear for the material-feeder in sewing machines, the combination in mechanism for imparting to the materialfeeder a movement in longitudinal direction, consisting of an oscillatable link, a rocking shaft, composed of one part which is not shiftable and of another part which is shiftable, two arms on said shiftable part of said shaft, a connecting rod connecting one of said arms with said link and composed of two parts one part mounted in the other so that it can rotate with regard to the same but not carry out a shifting movement, a cross bar carried by the said arms of said rocking shaft, and a material feed bar associated with the cross bar.

. In testimony whereof I aflix my signature.

RUDOLF MUNDLOS. 

